© 2016 QNAP Systems, Inc. All Rights Reserved.
Application Notes
April 2016
Create Microsoft Hyper-V Backups Using
QNAP Snapshot Agent and VSS Hardware
Provider
© 2016 QNAP Systems, Inc. All Rights Reserved.
Thank you for choosing QNAP products! This user manual provides detailed instructions of using the
Turbo NAS (network-attached storage). Please read carefully and start to enjoy the powerful functions of
the Turbo NAS!
The Turbo NAS is hereafter referred to as the NAS.
This manual provides the description of all the functions of the NAS. The product you purchased may not support certain functions dedicated to specific models.
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Table of Contents
Overview of the Volume Shadow Copy Service (VSS) ............................................................................... 4
Backup in large-capacity environments with ensured data integrity ................................................... 4
Volume Shadow Copy Service (VSS) ..................................................................................................... 4
VSS Hardware Provider and VSS operation .......................................................................................... 5
VSS Snapshot Agent and VSS operation ............................................................................................... 6
Backup software supporting VSS .......................................................................................................... 7
Preparation for installation ....................................................................................................................... 8
System requirements ............................................................................................................................ 8
Install Snapshot Agent ........................................................................................................................ 10
Connect to the ES NAS using Snapshot Agent .................................................................................... 11
Create iSCSI LUN snapshots .................................................................................................................... 15
Restore from iSCSI LUN snapshot ....................................................................................................... 18
Back up using QNAP NetBak Replicator and VSS H/W Provider ............................................................. 21
Configure NetBak Replicator to enable VSS ........................................................................................ 21
Using other backup software and VSS Hardware Provider .................................................................... 27
Acronis Backup .................................................................................................................................... 27
Symantec Backup Exec ........................................................................................................................ 29
Veeam Backup and Replication .......................................................................................................... 30
References .............................................................................................................................................. 34
© 2016 QNAP Systems, Inc. All Rights Reserved.
Overview of the Volume Shadow Copy Service (VSS)
Backup in large-capacity environments with ensured data integrity
Data centers that provide mission-critical services require their data storage to operate 24/7 without
service interruption. It is also important to have a well-rounded disaster and recovery plan for these
mission-critical data storages. However, large data sets can be cumbersome to back up using traditional
methods - often taking several hours or days for a complete backup. Moreover, traditional backup
methods lack mechanisms for maintaining data integrity. Data integrity relates to the insistent state of
data files; for example, files that are open or data stored in RAM or a cache. In mission-critical data
services, it is common to back up data while the applications that produce/modify data are still running.
When using inconsistent backup copies for system restoration, it may result in data loss or even
server/application failures if these backup files consist of application data or system state information.
To avoid these situations, we need a more intelligent backup method that can better protect data
integrity. We provide QNAP Snapshot Agent and VSS Hardware Provider to preserve data integrity. Along
with QNAP’s Snapshot technology, they simplify data protection and are more robust in system repair
scenarios.
Volume Shadow Copy Service (VSS)
The Volume Shadow Copy Service (VSS) is a set of COM interfaces that implements a framework to allow
volume backups to be performed while applications on a system continue to write to the volumes. It was
first introduced in Windows Server 2003 and offered view, clone and restore features for consistent
shadow copies (also known as a snapshot or a point-in-time copy).
A complete VSS solution comprises the following basic parts:
VSS Requester The is the software that requests the actual creation of shadow copies (or other high-
level operations like importing or deleting them). Typically, this is the backup application such as the
Windows Server Backup utility and APIs that request such service other backup software that runs on
Windows.
VSS Service The part of the Windows operating system that is in charge of the whole VSS process and
coordinates all of its parts to work together.
VSS Writer The VSS Writer instructs applications to perform required actions to create the volume
shadow copy when requested. VSS writers for various Windows components (such as the registry) are
included with the Windows operating system. This is typically included in VSS-aware applications, such
as SQL Server® or Exchange Server.
VSS Provider This component creates and manages the shadow copies. This can be either a software
or hardware based component. QNAP provides a VSS hardware provider for the ES NAS. A hardware
provider offloads the task of creating and maintaining a shadow copy from the host operating system.
© 2016 QNAP Systems, Inc. All Rights Reserved.
VSS Hardware Provider and VSS operation
The following diagram shows the components of Volume Shadow Copy Service (VSS), and the actions
required to create a consistent shadow copy (also known as a snapshot or a point-in-time copy) of the
data that is to be backed up.
To create a shadow copy, the components in the diagram perform the following actions:
1. The backup application (requester) asks VSS to enumerate the writers, gather the writer
metadata, and prepare for shadow copy creation.
2. The Volume Shadow Copy Service (VSS) notifies all the writers to prepare their data for creating
a shadow copy.
3. Each writer prepares the data as appropriate, such as completing all open transactions, rolling
transaction logs, and flushing caches. When the data is ready to be shadow-copied, the writer
notifies the VSS.
4. The VSS tells the provider to create the shadow copy.
5. The VSS provider creates shadow copy of the target volume.
6. The shadow copy is created.
7. The VSS releases file system write I/O requests. Applications are free to resume writing data to
the disk that is being shadow-copied.
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VSS Snapshot Agent and VSS operation
1. The NAS initiates backup requests and notifies Snapshot Agent to create the snapshot.
2. The Snapshot Agent asks Volume Shadow Copy Service (VSS) to enumerate the writers, gather the
writer metadata, and prepare for shadow copy creation.
3. The VSS notifies all the writers to prepare their data for making a snapshot.
4. Each writer prepares the data as appropriate, such as completing all open transactions, rolling
transaction logs, and flushing caches.
5. The Snapshot Agent tells the NAS to create the snapshot.
6. The shadow copy is created.
7. The VSS releases file system write I/O requests. Applications are free to resume writing data.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Backup software supporting VSS
Manufacturer Name License
Microsoft DiskShadow.exe As the operating system
QNAP NetBak Replicator Free
Acronis Acronis Backup Paid license and free trial
Altaro Hyper-V Backup Paid license and free
license with restrictions
ARCserve CA ARCserve Backup Paid license and free trial
Commvault Simpana 10 Paid license and free trial
DataCore SANsymphony-V Paid license and free trial
FastNeuron BackupChain Paid license
NAKIVO Backup & Replication Paid license
StorageCraft ShadowProtect Virtual Paid license and free trial
Symantec Backup Exec Paid license and free trial
Symantec NetBackup Paid license
Unitrends Enterprise Backup Paid license and free trial
Veeam Backup Free Edition Free
Veeam Backup & Replication Paid license and free trial
© 2016 QNAP Systems, Inc. All Rights Reserved.
Preparation for installation
System requirements
We have learned from previous sections that creating application-consistent snapshots is easy with the
QNAP Snapshot Agent and VSS Hardware Provider. Additionally, the underlying network architecture for
interconnecting the storage array (ES NAS) and the application server is not hard to implement. All of the
components (i.e. VSS Service, Requestor, Provider, and QNAP Snapshot Agent) can be installed on the
same server on which the VSS-aware applications reside.
In our demonstration, the following configurations and servers are used:
Storage device: QNAP ES NAS with QES 1.1.1 or newer.
Server: Windows Server 2008 (R2), Server 2012 (R2)
IP Settings: The QNAP Snapshot Agent and the ES NAS communicate over an IP network. For
better reliability, it is recommended that both the storage device and server use static IP
settings.
Servers and their Network Settings
Role IP Server Name Description
Application Server A 172.17.23.133 HV01 Hyper-V Host and
Snapshot Agent Server
Data Network A1 8.8.1.50 HV01 Data port 1 of HV01
Data Network A2 8.8.2.50 HV01 Data port 2 of HV01
ES NAS Network Settings
Setting Value Description
Storage Controller A (SCA)
Management IP
172.17.22.96 Management port’s IP address of
Storage Controller A (SCA)
Storage Controller A (SCA )
Ethernet1 IP
8.8.1.105 Data port 1’s IP address of Storage
Controller A (SCA)
Storage Controller A (SCA )
Ethernet2 IP
8.8.2.105 Data port 2’s IP address of Storage
Controller A (SCA)
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Storage Controller B (SCB)
Management IP
172.17.22.87 Management IP address of Storage
Controller B (SCB)
Storage Controller B (SCB )
Ethernet1 IP
8.8.1.106 Data port 1’s IP address of Storage
Controller B (SCB)
Storage Controller B (SCB )
Ethernet2 IP
8.8.2.106 Data port 2’s IP address of Storage
Controller B (SCB)
Storage pool owned by
Storage Controller A ( SCA)
Pool 1 Storage pool with RAID 60 configuration
owned by Storage Controller A (SCA)
iSCSI LUN iSCSI LUN on Pool 1
Before you begin installing the Snapshot Agent, verify the following prerequisites:
The .NET Framework 3.5 is installed on the Windows Server.
The VM and its applications to be backed up, including its settings, virtual disks and the default
location for virtual machine files have to be stored on the same iSCSI LUN.
Snapshot Agent cannot be installed if SMI-S Provider is already installed on the server.
The Snapshot Agent does not support iSCSI connections with MPIO configuration.
The Snapshot Agent does not support iSCSI connections with CHAP authentication.
Please do not install too many VMs on the same iSCSI LUN. The VSS writer will be overloaded
and may cause session time-out.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Install Snapshot Agent
1. Launch the Snapshot Agent installer, and click “Next” to continue.
2. Read the License Agreement. To accept the license agreement, click “I Agree”. Follow the on-screen
instructions to install the software.
3. Click “Finish” to close the installer.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Connect to the ES NAS using Snapshot Agent
1. Once you have completed the Snapshot Agent installation, open “QNAP Agent Manager”. You will
need to add the QNAP NAS that your Windows Server will be using as iSCSI storage by providing the
IP address or by clicking “Scan NAS” to automatically find the NAS on the local network.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Note: If the error message “The Network port (8097 or 9500) are not available, please check and turn off
the other application using port 8097 and 9500” appears, please exit Qfinder Pro if it is installed on the
computer. You can find the program that uses these ports by entering “netstat –ano” in Windows
PowerShell.
2. All QNAP NAS found will be listed. Double-click your ES NAS to connect to it.
© 2016 QNAP Systems, Inc. All Rights Reserved.
3. You will be asked to provide your NAS login credentials, to confirm the port for the connection, and
to enable the functions you want to install.
4. The Snapshot Agent will connect to the QNAP NAS and you can see the NAS been added to the list
on the main page.
Note: If the error message “Register SnapAgent for Windows on NAS <NASName> fails” appears when
you are trying to add the ES NAS to QNAP Agent Manager, please check the network connectivity and
firewall policy settings. Make sure that incoming TCP port 11169 is not blocked.
© 2016 QNAP Systems, Inc. All Rights Reserved.
5. Verify that the ES NAS has been successfully registered to your Windows Server.
To list the currently registered shadow copy writers, type” vssadmin list providers” in Windows
PowerShell:
6. Check that “QNAP VSS HW Provider” is listed. If the QNAP VSS HW Provider is not listed, please redo
the above steps to add the ES NAS.
7. It is possible to check if the agent is connected to the ES NAS from the QES. Log into the ES NAS as
an administrator, go to “Storage Manager” > “iSCSI Storage” > “Snapshot”, and then click
“SnapAgent”. A list of Snapshot Agents that are currently connected to the ES NAS will be displayed.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Create iSCSI LUN snapshots
In this section and following sections, we will demonstrate how to create application-consistent
snapshots without taking the volumes offline or suspending the applications that write on the volumes.
Before taking an iSCSN LUN snapshot, please make sure that an iSCSI LUN has been created on the NAS.
And the iSCSI LUN has been connected and used by the Windows Server. In our demonstration, we also
created 6 VMs on the Windows server using Hyper-V Manager.
Use the following procedure to create iSCSI LUN snapshots
1. Log into the ES NAS as an administrator, go to “Storage Manager” > “iSCSI Storage”, select an
iSCSI LUN, and then from the “Snapshot” drop-down menu select “Take a Snapshot”.
© 2016 QNAP Systems, Inc. All Rights Reserved.
2. The “Take a Snapshot” screen appears. Give a name for the snapshot and select the duration to
keep the snapshot. Then select the appropriate snapshot type. Click “OK’ to start taking the
snapshot. The crash-consistent snapshot backups up only data on the disk whereas the
application-consistent snapshot backs up data from the disk, cache and memory. Moreover, to
create a consistent view of application data during the course of the backup, the application-
consistent backup needs Snapshot Agent whereas the crash consistent does not.
3. Log into the Hyper-V Manager, you can see the status of all virtual machines shows “Backing up”
and the Checkpoints also indicate the time of the snapshot. The Snapshot Agent helps quiet a
VM file system just prior to a backup.
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4. The backup will take a few minutes if there are not many VMs. When the job is completed, the
QES will display a message saying that the snapshot has been created.
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Restore from iSCSI LUN snapshot
The snapshots can be used to quickly restore a VM to a previous point in time. Before starting a restore
operation, please disconnect the host’s iSCSI connection to the NAS. Therefore, it is recommended that
users should shut down the VMs for system recovery.
1. Log into the NAS as an administrator, go to “Storage Manager” > “iSCSI Storage”, and then select the
LUN to be restored. Select “Action”, and then select “Disabled” to disable the iSCSI LUN.
2. Select “OK” when you are prompted for confirmation.
3. Select “Action” and then select “Un-map” to un-map an iSCSI LUN to an iSCSI target.
© 2016 QNAP Systems, Inc. All Rights Reserved.
4. The LUN should be listed in the “Un-Mapped iSCSI LUN List”. Select the LUN and click “Snapshot” >
“Snapshot Manager” to list all of its snapshots. Then select a snapshot to be restored and click
“Revert”.
5. A message appears to notify you that newer snapshots will be deleted after the restoration. Select
“OK” to continue.
6. Select “OK” to complete the restoration.
7. To map the iSCSI LUN back to its target, select “Action” and select “Map”.
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8. Select which iSCSI target to be mapped back to, and then select “Apply”.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Back up using QNAP NetBak Replicator and VSS H/W Provider
NetBak replicator is a free and easy-to-use backup program that supports VSS. With QNAP NetBak
replicator, you can back up transactional-based applications such as databases and virtual machines. VSS
can facilitate creating backup files with a consistent view and without data corruption. When you
conduct a backup job for an iSCSI LUN from the Windows Server with backup software that supports
VSS, the VSS Hardware Provider will use NAS ROW (Redirect on Write) instead of Windows COW (Copy
on Write) to take snapshots on the Windows Server and therefore increase the backup efficiency. The first
step to use VSS hardware provider function is to configure your backup software to enable VSS as
described in the following sections.
Configure NetBak Replicator to enable VSS
1. Select “Advanced Mode” in the lower-left corner, and then select “Options” > “Advanced Settings”.
2. Click the “Backup Settings for Opened Files” button.
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3. Select both “Enable VSS” and “Enable VSS Writer” options.
4. Select the “Instant Backup” tab. Select the backup source where the Hyper-V VMs are stored, select
the destination, and then select “Start Backup” to start the backup job.
© 2016 QNAP Systems, Inc. All Rights Reserved.
5. Log into the NAS, and go to “Storage Manager” > “Snapshot” > “Snapshot Manager”. You should see
that a snapshot named VSS_snap_# has been created successfully.
6. After the snapshot has been created, another iSCSI LUN called “vss_clone#” (in “iSCSI Storage” >
“iSCSI Target List”) will be temporary created for the backup job.
© 2016 QNAP Systems, Inc. All Rights Reserved.
7. In the Hyper-V Manager, you can find that the status of the VMs shows “Backing up”.
8. You can check backup progress from the NetBak Replicator.
© 2016 QNAP Systems, Inc. All Rights Reserved.
9. A screen appears, showing the number of files being backed up and the duration of time for the
backup.
10. To restore with the backup file, please click the “Instant Restore” tab, choose the backup source in
the left pane and the backup destination in the right pane. Also select what you would like to do
when a file with the same name but different content exists during the restore process. Click “Start
Restore” to start the restore job.
© 2016 QNAP Systems, Inc. All Rights Reserved.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Using other backup software and VSS Hardware Provider
Acronis Backup
Use the following procedure to enable VSS in Acronis Backup.
1. Launch the Acronis Backup software and select “Manage this machine”.
2. Select “Options” > “Default backup and recovery options”.
3. Select “Default backup options” in the left pane to expand the options.
© 2016 QNAP Systems, Inc. All Rights Reserved.
4. Select “Volume Shadow Copy Service” and its detailed configurations will appear in the right pane.
Select “Use Volume Shadow Copy Service” and choose “Hardware” for Snapshot provider. Then click
“OK” to finish the configuration.
© 2016 QNAP Systems, Inc. All Rights Reserved.
Symantec Backup Exec
Use the following procedure to enable VSS in Symantec Backup Exec.
1. Launch Symantec Backup Exec and select “Backup and Restore” > “Backup” > “Back Up to Disk”.
2. Select “Edit” in the lower right corner of the screen.
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3. Select “Advanced Open File” from the left menu. Enable “Use snapshot technology” and then select
“Hardware” from the “Snapshot provider” drop-down menu.
Veeam Backup and Replication
Use the following procedure to enable VSS in Veeam® Backup and Replication™.
1. Launch Veeam Backup and Replication program, select the target server in the list, and then select
“Manage Volumes”.
2. Since the target server already has QNAP Snapshot Agent installed, the two iSCSI LUNs with QNAP
VSS HW Provider are displayed in the list.
© 2016 QNAP Systems, Inc. All Rights Reserved.
3. Select “Backup & Replication” in the lower-left corner, and then click “Backup Job”.
4. Follow the on-screen instructions to create a backup job.
© 2016 QNAP Systems, Inc. All Rights Reserved.
5. In the Guest Processing configuration window, select “Enable application-aware processing” to
enable Microsoft VSS. Then click “Credentials” and enter the login credentials for the VMs that you
want to back up. Click “Next” to proceed.
© 2016 QNAP Systems, Inc. All Rights Reserved.
6. You can configure scheduled backup or click “Create” to create one time backup now. Then click
“Finish” to complete the setup of a backup job.
© 2016 QNAP Systems, Inc. All Rights Reserved.
References
Volume Shadow Copy Service. (September 3, 2014). Retrieved from https://technet.microsoft.com/en-
us/library/ee923636(v=ws.10).aspx
15827: Acronis Backup & Recovery: Backing Up and Restoring Domain Controller. Retrieved from
https://kb.acronis.com/content/15827
How to configure System provider to perform snapshot backups of Backup Exec explicitly when Backup Exec and Backup Exec System Recovery coexist. (September 14, 2015). Retrieved from https://www.veritas.com/support/en_US/article.TECH73202 Veeam Help Center. (March 18, 2015). Retrieved from https://www.veeam.com/documentation-guides-
datasheets.html